The subject matter disclosed herein relates to an ultrasonic imaging apparatus and, particularly, relates to an ultrasonic imaging apparatus that captures a plurality of B-mode images of a same cross section respectively by a plurality of linear scans with different directional ultrasonic beams and creates and displays a compound image from these B-mode images.
An ultrasonic imaging apparatus scans a range to be imaged with an ultrasonic beam, generates a B-mode image from echo signals received, and displays the image. Some ultrasonic imaging apparatus captures a plurality of B-mode images of a same cross section by a plurality of linear scans with different directional ultrasonic beams respectively and creates and displays a compound image from these B-mode images (refer to, e.g., Japanese Published Unexamined Patent Application No. 2006-095151).
The ultrasonic imaging apparatus is also used as support equipment when an invasive treatment on a living body is performed. In particular, for example, when a needle is inserted into the body toward a target within the body, an image in which the target and the needle are tracked within a same FOV (Filed of View) is captured and displayed and this image is used as guidance or navigation for needle insertion (refer to, e.g., U.S. Pat. No. 6,733,458).
For images used for guidance or navigation for invasive treatment, a proper FOV (Field of View) and a high image quality are required. A proper FOV is necessary for bringing an invasive medical device such as a needle entirely into view and a high image quality is necessary for visualizing clear images of both the target and the invasive medical device.
A convex scan or a virtual convex scan is performed to obtain an FOV suitable for invasive treatment. In these scans, however, because the density of acoustic lines decreases in a far field, a decrease in the image quality is inevitable.